Written by: Clive Harris
Using a cordless strimmer is an excellent way to achieve a tidy lawn, with none of the back-breaking effort of using lawn shears or scissors.
Compared to other designs, cordless grass trimmers are one of the best options to go for – you’re not held back by a mains cable, or the weight of a petrol strimmer.
Often, corded electric strimmers need to be used with an extension lead in the garden, and this can be a lot of effort. By comparison, a cordless trimmer save a lot of hassle. Ultimately, if the strimmer is easy to use, you’ll be more likely to get it out the shed.
If you’re after a new cordless grass trimmer, there are a few things to bear in mind to make sure you’re getting the best one. The information below should give you an idea of what to look out for, and also what to avoid:
How Grass Trimmers Work
Grass trimmers tend to use one of two cutting mechanisms: a cutting line, or cutting blades.
Here’s a description of each type, as well as their pros and cons.
Cutting Line Strimmers
Cordless trimmers that use a cutting line have one or two lines of nylon string inside the head of the strimmer. They cut using centrifugal force; whilst the line is no good for cutting when at rest, it becomes stiff and blade-like when it spins quickly.
As the line wears down, new line needs to be fed into the cutting head from the spool. Sometimes this is done manually, but most cordless trimmers have a system in place to make this process automatic or semi-automatic.
There are two main systems for distributing more line: ‘bump feed’ and ‘automatic feed’.
Strimmers with a ‘bump feed’ system require you to ‘bump’ the end of the strimmer on the ground to release more line. This means that you’re in control of when to release more line, and can help control how quickly it is used.
‘Automatic feed’ strimmers release more line each time the machine is turned back on. This can help ensure you’re never using weak, blunt line. However, it can sometimes result in using line too fast, which becomes expensive. If you’re using a cordless grass trimmer, you’ll likely keep turning off the unit to save battery as you move around the garden. It can therefore be wasteful if new line is automatically released each time you turn the unit on.
Some people prefer the automatic system to the ‘bump feed’ system, you just need to be aware that it could use more line.
There are also single-line and double-line strimmers. Single-line strimmers have less cutting force than double-line strimmers, but that isn’t necessarily a bad thing. It just depends what job you are doing. Some people find that a grass trimmers with a double cutting line is too strong: they can damage tree trunks, flower pots or fencing if you get too close.
A design which is slowly growing in popularity, bladed strimmers generally have two nylon blades on the head of the strimmer which spin at speed. As they spin, they generate a lot of cutting power.
The blades are replaceable, and generally you’ll need to replace a blade after every 2 hours of use. This is because they can get damaged, and occasionally they’ll come off and get lost in the garden.
Generally, about 10 – 20 spare blades will come included with the strimmer, with replacement packs of around 30 blades available for about £10 online.
In terms of cutting power, blades and cutting line are pretty evenly matched. Some gardeners have grown tired of messing with cutting line and prefer the bladed models, but others don’t enjoy having to replace the blades.
How to Use a Cordless Strimmer
Cordless strimmers naturally require you to be slightly more organised compared to mains-powered tools – charging the battery needs to be done in advance to avoid disappointment when it’s time to tackle the garden.
If you don’t wear the battery all the way down, you’re unlikely to need to recharge it before using it again; the lithium-ion batteries used in cordless tools hold their charge relatively well. Of course, charging before use will make sure that you get the most run-time possible from your cordless machine.
Generally speaking, using a cordless grass trimmer is quite intuitive. There is usually a simple start button which will start the motor going. Some machines have a safety button as well as a start trigger, requiring both to be pushed to avoid accidental start-ups.
It may take a bit of practise initially, as well as trial and error, to work out where the cutting line is, but it doesn’t take long to master.
One side of the grass trimmer will host the cutting edge, and debris will shoot out from the other side. Experiment until you know which is which, otherwise you’ll walk against the cutting direction.
Go slowly with the strimmer regardless of whether it’s an edging job or a tougher task – rushing can cause an uneven cut (and can also be dangerous) so it’s better to take your time to avoid having to go back over the same spot twice. With tougher plants, it can help to tackle them in sections. If a cordless trimmer can’t immediately tackle the thick stem of a weed, it can help to cut from the top down and cut it gradually.
Finally, look out for tripping hazards. Bricks, small fences, garden ornaments, cats, dogs and small children can all trip you up when you’re concentrating on creating a perfect line. It’s best to clear the parameters first, just to be sure.
Why Choose Cordless Over Mains Powered?
Cordless trimmers and mains-powered trimmers work well in the garden. Petrol models are also available, although they’re less commonly used for domestic use so here we’re going to focus on electric models. There are pros and cons to cordless and mains-powered strimmers, which are covered below:
Mains Powered Strimmers
Mains-Powered grass trimmers are powerful and there’s no battery to run down – their run-time is essentially limitless. They can often cut through slightly thicker vegetation than battery-powered models.
However, these strimmers can cause problems sometimes. Some people worry about cutting through the cord with the strimmer, which is easier to do than you might think. Also, as mentioned above, mains-powered strimmers limit you in terms of where you can go in the garden. Generally, they have a mains cable of up to 10 m long, so for anything larger than a small garden, or for reaching awkward places, an extension cable will be needed. This can be a hassle, as well as a tripping hazard.
Battery-powered strimmers have a limited amount of run-time before you need to stop and charge them. However, how long the battery lasts for depends on its size and power. Some cordless grass trimmers will have a battery than only lasts 20 minutes, but others (normally with a battery of 4 Ah or more) can last around 30 – 40 minutes depending on the job.
Naturally, one of the main benefits of a battery-powered strimmer is that they are much easier to manoeuvre than their corded counterparts. Not only is there no potentially-hazardous cord to accidentally cut or trip over, but there’s no cord restricting your movement either.
As with a lot of things, personal preference will likely dictate whether you choose a mains-powered or battery-powered strimmer. It also depends on the job you are doing, whether you need slightly more power with a mains-powered option, or prioritise the freedom of cordless tools.
In terms of power, there is now some crossover between battery-powered models and mains-powered ones, especially in the mid-range price bracket. So, the biggest caveat is the battery run-time of cordless strimmers. This is something that has greatly improved over the last couple of years, so it’s best to look for a tool that has 30 – 40 minutes run time. 20 minutes may not be enough. Of course, if you buy more batteries, you can keep swapping them out to continue with the job. There are few strimming jobs that will really require more than an hour’s work, making cordless a no brainer for a lot of people.
Choosing the Most Comfortable Design
Here are a few things to look out for when looking for the best grass trimmers:
- Handles – an ergonomic handle is a great plus, and a second handle further down the shaft makes strimming much easier. The second handle balances out the weight to avoid ending up with one aching arm. The design of the second handle can differ, and some people find a real handle more comfortable than just a raised hand-hold.
- Telescopic shaft – Adjustable shafts help you find the perfect working height and save on backache. More powerful strimmers should have a longer reach so you can hold them away from your toes. (This is a good place to say you should never strim the lawn in flip flops. Always wear sturdy boots!)
- A cutting style that you get on with – as mentioned above, strimmers can use either cutting line or cutting blades. Keep this in mind when shopping, and decide if you’re more comfortable (physically and economically speaking) replacing wire or blades when it wears out.
Wearing the Correct Attire
Protective clothing such as ear defenders for louder motors with more power can be useful, particularly if the job is going to take a while. This is particularly relevant for a petrol strimmer, but certain electric trimmers can also be very loud.
Sturdy boots are a must, and you should avoid wearing loose trailing clothes that could get caught in the strimmer.
If you’re cutting overgrown areas, protective glasses are important because strimmers can throw up stones and other sharp objects.
Wear gloves to protect your hands whilst strimming, and be aware of the need to take frequent breaks – especially if the machine vibrates a lot.
A Warning About Strimmers and Wildlife
It would be remiss not to mention the injuries strimmers can inflict on harmless wildlife.
They are great bits of kit, but use them mindfully to avoid inflicting unnecessary damage and pain.
Always rake through long grass or undergrowth first, before using cordless grass trimmers. This gives hedgehogs, frogs, toads, grass snakes, newts, mice and all our native wildlife a chance to escape.
Bear in mind that creatures like hedgehogs would rather curl up to avoid danger, so make sure you move any garden furniture, watch what you’re doing and never put a cordless trimmer somewhere you can’t see the cutting line.
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